Hi Dave,
 
Check out John Deck's blogg.
http://johndeck.blogspot.com/2005/09/overlaying-mercator-projected-wms.html
 
Google map's projection is Mercator, but uses lat long as units (rather than metres). I think there's something that Mapserver does with bounding boxes that other WMS don't do. I haven't successfully got a WMS overlaid correctly using my mapserver WMSs (3.6.1 and 4.0). I've got close using John Deck's method, but suffer tile alignment issues that don't affect other WMS servers.
 
Might also be worth checking out Mapbuilder. I understand they have a _javascript_ Mercator/Lat long conversion function. It may be more accurate than the one John Deck uses.
 
 
Steve
 
 


From: UMN MapServer Users List [mailto:[EMAIL PROTECTED] On Behalf Of Dave Brown
Sent: November 6, 2005 9:38 AM
To: [email protected]
Subject: [UMN_MAPSERVER-USERS] Google maps projections..

Could any one help me setting the correct parameters for overlaying my vector maps (latlong wgs84) over google maps imagery ?
 
I have the right bounds etc.. and when I dont specify the projections at all, the correct data is overlayed but the projection is off..
 
I am experimenting with mapserver as I want to move away from mapxtreme,   which in mapxtreme I used to render the map in mercator projection/Nad27 but whatever I seem to do in mapserver, I get incorrect results..
 
I using OGRINFO on one of my MI .TAB files the projection info is...
 
GEOGCS["unnamed",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563],
        TOWGS84[0,0,0,0,0,0,0]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433]]
 
Any help greatly appreciated.
 
Thanks,

Dave.

--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.362 / Virus Database: 267.12.7/159 - Release Date: 02/11/2005

Reply via email to